CODEWITHSUNDEEP
javaswingjpanelgraphics2dmouselistener
ravensgo
ravensgo

Reputation: 522

Graphics are blocked out when I add a JPanel to the frame (java)

I have some Graphics2D graphics displayed in my frame, and then I added a JPanel to the entire frame so that I can add a mouselistener to clicks anywhere in the panel. However, the graphics disappear, I assume blocked out by the frame. I tried setting the panel to visible false, but that didnt do anything. How can I keep my mouselistener listening on the entire window, and still display my graphics?

EDIT: Heres a bit of code: EDIT:(and some more)

//adding the panel and mouselistener
JPanel allPanel = new JPanel();
allPanel.addMouseListener(this);
frame.add(allPanel);


//...
//drawing some of the graphics
public void draw() {



    frame.add(new CustomPaintComponent());
    // Display the frame

    frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE); 
    frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
    frame.setVisible(true);
    JPanel allPanel = new JPanel();
    allPanel.addMouseListener(this);
    frame.add(allPanel);
      }


      static class CustomPaintComponent extends Component {

        private static final long serialVersionUID = 1L;

    public void paint(Graphics g) {

      Graphics2D g2d = (Graphics2D)g;
      g2d.fillRoundRect(10, 10, 50, 50, 10,10);

      //...

Upvotes: 0

Views: 261

Answers (2)

MadProgrammer
MadProgrammer

Reputation: 347184

Three problems jump out...

First, JFrame uses a BorderLayout as its default layout manager, this means that only one component can occupy any of its available five positions. By using add(Component) you add each component to the CENTRE position, overriding the first component you added to it...

Second, JPanel is opaque by default, meaning, even if you did get both components to occupy the same space, the top component would block the lower one

Third, you should be using paintComponent instead of paint

Take a look at Performing Custom Painting for more details

The solution could be to add the MouseListener directly to the custom component

Another choice would be to use a BorderLayout on the lower component, make the top component transparent (using setOpaque(false)) and add it to the lower component directly...

Upvotes: 4

Justin
Justin

Reputation: 25277

I believe your problem is that JFrame can have only one component added to it (by default). You add a CustomPaintComponent, which paints your graphics. Then, you add the JPanel, which automatically removes the CustomPaintComponent

Are you trying to paint the custom drawing on top of the JPanel? If that is the case, simply move that code over to the JPanel (but instead of using a CustomPaintComponent, put it in the paintComponent(Graphics g) method of the JPanel)

Upvotes: 4

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